Get a list of Observation objects.

### Available end points:

- `/observations/` - Will list all Results in the database
- `/observations.json` - Will return all Results in json format. This can
also be achieved by using the accept header. `application/json`
- `/observations/<object_id>/` - Returns Results object with that id

### Available Methods:

- `GET`
- `HEAD`

### Available filters:

- `title`
- `uuid`
- `keywords`
- `status`
- `result_field`
- `discoveryKeywords`
- `updateFrequency`
- `nonGeographicFlag`
- `publicationState`
- `permissions`

### How to use filters:

These filters can be used like django query filters using __ for related model relationships.

- `/observations/?uuid=d594d53df2612bbd89c2e0e770b5c1a0`
- `/observations/?status=completed`
- `/observations/?results_field__dataPath__startswith=/neodc/esacci`
- `/observations/?discoveryKeywords__name=ESACCI`
- `/observations/?nonGeographicFlag=True`

Filters can be stacked to build an 'AND' relationship. E.g.

- `/observations/?publicationState__in=published,citable&nonGeographicFlag=True`
- `/observations/?publicationState__in=published,citable&discoveryKeyword__name=NDGO0003`

GET /api/v2/observations/27274/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 27274,
    "uuid": "0d05cf74e17f49c2b7c5cd02faa59291",
    "title": "University of Bath: Ascension Island Skiymet Meteor Radar data (2005-2012)",
    "abstract": "The University of Bath's Ascension Island meteor radar (7.9 S, 14.4 W) is an all-sky VHF (Very High Frequency) meteor radar commercially produced Skiymet system. The system was operational from October 2001 to June 2011, albeit with some gaps in the data coverage, in support of a number of research projects - see linked Project records for further details. Meteor detection and derived wind data from this instrument were collected in support of a number of research projects - see linked Project records for further details.\r\n\r\nThe radar detects radio scatter from the ionised trails of individual meteors drifting with the winds of the upper mesosphere, mesopause and lower thermosphere. A low-gain transmitter antenna is used to provide broad illumination of the sky. An array of five receiver antennas act as an interferometer to determine the azimuth and zenith angles of individual meteor echoes. Doppler measurements from each meteor determine the radial drift velocity and the meteor is assumed to be a passive tracer of atmospheric flow. The radar typically detects of order a few thousand meteors per day. These observations can be used to determine zonal and meridional winds in the mesosphere, mesopause and lower thermosphere at heights of about 80 – 100 km and with height and time resolutions of ~ 3 km and 2 hours.\r\n\r\nThe radar produces daily “meteor position data” data files (mpd files) recording the details of each individual meteor echo. In normal operation a few thousand individual meteors are detected per day. See parameter list for details of available data.\r\n\r\nRecordings are made for each individual meteor detected allowing measurements of zonal and meridional wind speeds in the mesosphere and lower thermosphere to be obtained. Meteor count rates vary diurnally and with season, but are usually up to a few thousand meteors per day.",
    "keywords": "meteor radar, mesosphere",
    "publicationState": "published",
    "dataPublishedTime": "2019-06-03T13:21:23",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27275/?format=api",
        "dataPath": "/badc/meteor-radars/data/ascension/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 2317630317,
        "numberOfFiles": 4526,
        "fileFormat": "Data are ASCII formatted. See documentation for details."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7315/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2292/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27550/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27551/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27552/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27555/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27556/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27557/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27558/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/27559/?format=api"
    ],
    "dataLineage": "Data from the instrument are produced by the instrument's SKiYCORR analysis programme before being collected by Genesis Software, the instrument manufacturer, who then supplied the data to the Centre for Environmental Data Analysis (CEDA) for long-term archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27258/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27261/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27264/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27266/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/27283/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114066/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114064/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114065/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114067/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114070/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114071/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114063/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114069/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114068/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114072/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/27279/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2522/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}